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HIV and schistosomiasis programmes should be combined to reduce the spread of HIV

Testing and treatment programmes for HIV and schistosomiasis (also known as snail fever or bilharzia) could be profitably combined
in settings with a high prevalence of both infections, results of a study
published in PLOSNeglected Tropical
Diseases suggest.

Retrospective
research involving over 1000 HIV-serodiscordant couples in Lusaka, Zambia, showed
that infection with schistosomiasis was associated with an increased risk of
HIV transmission from HIV-positive to HIV-negative partners, an increased risk
of HIV acquisition among women, and an increased risk of death for HIV-positive
women.

The authors note
that schistosome infections can be safely, effectively and cheaply treated with the anti-worm medication praziquantel. “Schistosomiasis prevention and treatment strategies may be a
cost-effective way to reduce not only the symptoms associated with the
infection, but also new cases of HIV and death among HIV+ persons,”
they suggest.

A serodiscordant couple is one in which one partner has HIV and the other has not. Many people dislike this word as it implies disagreement or conflict. Alternative terms include mixed status, magnetic or serodifferent.

The general term for the body’s response to injury, including injury by an infection. The acute phase (with fever, swollen glands, sore throat, headaches, etc.) is a sign that the immune system has been triggered by a signal announcing the infection. But chronic (or persisting) inflammation, even at low grade, is problematic, as it is associated in the long term to many conditions such as heart disease or cancer. The best treatment of HIV-inflammation is antiretroviral therapy.

Schistosomiasis is an infection caused by a parasitic worm that lives in fresh water. People become infected when the larvae – released by freshwater snails – penetrate the skin during contact with infested water. An estimated 200
million people have schistosomiasis worldwide and 90% of these infections are
in sub-Saharan Africa.

Common types of the infection in sub-Saharan Africa are Schistosoma haematobium and Schistosoma mansoni, which cause
urogenital and intestinal schistosomiasis, respectively. Most infections occur
in childhood, and prevalence is generally higher in rural than urban settings.

The infection can
cause a localised immune response and genital lesions. It may therefore
increase the risk of HIV transmission and acquisition.

To see if this is
the case, investigators designed a retrospective study involving
HIV-serodiscordant couples recruited in Lusaka between 1994 and 2012.

At baseline, participants were
tested for schistosome-specific antibodies (which may reflect either active or previous infection). The association between
schistosome antibody status and HIV transmission, acquisition and mortality
risk was then examined.

The 1046 male and 1099 female participants were
followed for an average of 800 days. A fifth of men and 12% of women died
during follow-up. Antiretroviral therapy was started by 10% of men and 8% of
women.

Baseline
schistosomiasis was significantly associated with mortality in HIV-positive women,
even after controlling for confounders that included HIV viral load (aHR =
1.97; 95% CI, 1.19-3.25, p = 0.008). No such association was detected in HIV-positive
men.

The researchers say their findings show the importance of schistosomiasis treatment and prevention, which should be integrated into HIV programmes. As well as reducing schistosomiasis-related illness, it could help prevent HIV transmission and mortality.

“Praziquantel treatment for schistosomiasis is safe, including in pregnant
women, has no reported widespread drug resistance, has only moderate
side-effects, and can be dispensed via community-wide mass administration," they write. "Additionally, praziquantel may attenuate HIV replication by decreasing systemic
inflammation and slow HIV disease progression.”

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The National Institutes of Health has awarded approximately $11.3 million to 23 institutions across the United States to collaborate with community partners to develop locally relevant plans for diagnosing, treating and preventing HIV in areas with high rates of new HIV cases.

The former CEO of Lloyd’s bank will head an independent commission to end HIV transmissions in England. UK HIV charities, Terrence Higgins Trust and NAT (National AIDS Trust) created the HIV Commission. The year-long independent commission has the backing of the UK government.

Universal test-and-treat strategies resulted in "modest to no reductions" in new HIV transmissions in three large population-based studies, writes Salim Abdool-Karim, MD, ChB, PhD, of the Centre for the AIDS Programme of Research in South Africa, in a commentary published online today in the New England Journal of Medicine.

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